HIV testing in patients presenting with indicator conditions in outpatient settings: offer and uptake rates, and educational and active interventions.

Approximately 13% of people living with HIV in the UK are undiagnosed which has significant implications in terms of onward transmission and late diagnosis. HIV testing guidelines recommend routine screening in anyone presenting to healthcare with an HIV indicator condition (IC); however, this does not occur routinely. This study aimed to assess the feasibility and effectiveness of using case note prompts highlighting the presence of an IC to increase HIV testing. Clinicians in three outpatient departments received case note prompts either before or after a period of clinician-led identification. Test offer and uptake rates were assessed. A parallel anonymous seroprevalence study estimated the prevalence of undiagnosed HIV. A total of 4191 patients had an appointment during the study period; 608 (14.5%) had an IC. HIV test offer was significantly higher when a prompt was inserted into notes (34.3% versus 3.2%, p < 0.001). The prevalence of diagnosed HIV in the cohort was 4.1%. No cases of undiagnosed HIV infection were identified. Despite guidelines, offer of HIV testing is low. Strategies to increase routine screening of patients presenting with an IC are needed. Individual case note prompts significantly increase HIV test offer; however, the effect is lost if the strategy is withdrawn.

Transmission of Staphylococcus aureus between health-care workers, the environment, and patients in an intensive care unit: a longitudinal cohort study based on whole-genome sequencing.

BACKGROUND: Health-care workers have been implicated in nosocomial outbreaks of Staphylococcus aureus, but the dearth of evidence from non-outbreak situations means that routine health-care worker screening and S aureus eradication are controversial. We aimed to determine how often S aureus is transmitted from health-care workers or the environment to patients in an intensive care unit (ICU) and a high-dependency unit (HDU) where standard infection control measures were in place. METHODS: In this longitudinal cohort study, we systematically sampled health-care workers, the environment, and patients over 14 months at the ICU and HDU of the Royal Sussex County Hospital, Brighton, England. Nasal swabs were taken from health-care workers every 4 weeks, bed spaces were sampled monthly, and screening swabs were obtained from patients at admission to the ICU or HDU, weekly thereafter, and at discharge. Isolates were cultured and their whole genome sequenced, and we used the threshold of 40 single-nucleotide variants (SNVs) or fewer to define subtypes and infer recent transmission. FINDINGS: Between Oct 31, 2011, and Dec 23, 2012, we sampled 198 health-care workers, 40 environmental locations, and 1854 patients; 1819 isolates were sequenced. Median nasal carriage rate of S aureus in health-care workers at 4-weekly timepoints was 36·9% (IQR 35·7-37·3), and 115 (58%) health-care workers had S aureus detected at least once during the study. S aureus was identified in 8-50% of environmental samples. 605 genetically distinct subtypes were identified (median SNV difference 273, IQR 162-399) at a rate of 38 (IQR 34-42) per 4-weekly cycle. Only 25 instances of transmission to patients (seven from health-care workers, two from the environment, and 16 from other patients) were detected. INTERPRETATION: In the presence of standard infection control measures, health-care workers were infrequently sources of transmission to patients. S aureus epidemiology in the ICU and HDU is characterised by continuous ingress of distinct subtypes rather than transmission of genetically related strains. FUNDING: UK Medical Research Council, Wellcome Trust, Biotechnology and Biological Sciences Research Council, UK National Institute for Health Research, and Public Health England.